The greatest mass extinction pulse was the Permian-Triassic extinction event, and it happened about 250 million years ago, nearly wiping out life on Earth. It was Earth’s most severe extinction even, with 96% of all marine species and 70% of all terrestrial vertebrate species becoming extinct. It is the only known mass extinction that affected insects, 57% of all families and 83% of all genera were extinguished.
Read more @ SciTechDaily
